The present invention relates generally to a transmission having a main section and an auxiliary section and more particularly to a transmission in which the main section and auxiliary, section can each be removed and serviced independently of the other.
The present invention relates to those transmissions having main sections connected in series with auxiliary sections. Generally a main shaft is rotatably mounted along with one or more main countershafts in a main case. The main case generally comprises a generally cylindrical sidewall having a removable front wall and an integral intermediate wall opposite the front wall. The auxiliary section includes an auxiliary shaft and one or more auxiliary countershafts mounted in an auxiliary case having a generally cylindrical sidewall integral with a rear wall. The auxiliary case is removably secured to the main case adjacent the intermediate wall. Bearings in the intermediate wall support the main shaft and countershafts.
Assembly of the known transmission is difficult. Shafts and gears must be loaded through the front cover opening. The bearings are difficult to install and are easily damaged during the assembly process. Timing of the main shaft with the countershafts is difficult because the countershafts must be supported while assembling the main shaft. Service of the main section in the known transmission is also difficult. In order to access the main section of the transmission, the auxiliary case must also be removed. Further, some bearings must be removed before the main section can be disassembled.
The present invention provides a transmission having an intermediate plate between the main case and the auxiliary case which is removably mounted to the main case and the auxiliary case. The intermediate plate also supports the bearings for the countershafts and the main shaft. As a result, each of the main case and auxiliary case can be removed from the intermediate plate without disturbing the other.
Preferably, the main case and the auxiliary case each include a flange adjacent the intermediate plate. A plurality of long bolts are inserted through apertures in the flange of the auxiliary case, apertures through the intermediate plate and threaded into threaded bores in the flange of the main case. Further, a plurality of short bolts are inserted through apertures through the flange in the main case and threaded into bores in the intermediate plate. Similarly, short bolts are inserted through apertures in the flange of the auxiliary case and threaded into threaded bores in the intermediate plate. Preferably, the threaded bores in the intermediate plate extending from the front surface are coaxial with those extending from the rear surface. During disassembly, all of the long bolts are removed. Then, only half of the short bolts are removed, i.e. either those short bolts securing the main case to the intermediate plate or those short bolts securing the auxiliary case to the intermediate plate. Therefore, the main case or the auxiliary case can be removed while the other case is retained by the remaining short bolts.